More than 2000 sample analyses were performed in support of other NIEHS scientists. Collaborative research problems have included: characterization of metabolites of phthalates and diethylstilbestrol, measurement and identification of chlorinated dibenzo-p-dioxins and dibenzofurans in soil and animal tissues; estimation of 3-methoxy-4-hydroxyphenylglycol in rat brain; identification of physalemine-like peptides and epidermal growth factor in tissues; identification of corticosterone metabolites in mammary gland; and characterization of phospholipids.